I agree with the potential trade back.
However, I strongly thing that a.) Buckner will be gone at #6, and b.) Ozzie won't pick Bosa even if he's still on the board at #6 (which more and more mocks project will be the case).
Why? Ozzie and the Ravens scouting team has a great track record identifying capable pass rushers that are still available on day#2. Three names: JJ, McPhee, Za'Darius Smith. All three were day#2 picks. And there will be promising pass rusher talent on day#2. Therefore, I think Ozzie won't go for a pass rusher with his top picks.
And, since retaining Shareece Wright means we have our starting CB tandem, the most logical and safest bet for #6 seems to be Ronnie Stanley - as I'm positive KO will be gone the first day of free agency - meaning that although we have Urschel and probably Jensen, a top talent at G would be a logical pick. Or a trade down. And, as a trademark Ozzie-move, drafting our next great pass rusher in the 4th round, with one of the picks acquired in the trade
I wouldn't bank on Wright being the locked in starter. He played mediocre at best last year. We played some really bad QB's when he started getting playing time and he wasn't overwhelming. He is an upgrade to Arrington who can't cover anyone anymore. BTW Wright's resume is not great, but he did play better in 2015 than he had previously. https://www.profootballfocus.com/blog/2014/05/13/best-fantasy-cb-matchups/ https://www.profootballfocus.com/blog/2015/02/13/sig-stats-ypcs-cornerbacks/ His contract: 3YR $16M.